DESCRIPTION (Adapted from Applicant's Description): The goal of this Mentored Research Scientist Development Award is to allow the applicant to develop the research skills necessary to be independent in the investigation of movement impairments in people with spinal pain conditions using clinical and instrumented measures. The long term goals of the proposed research are to understand the nature and specificity of the movement impairments found in spinal pain conditions and to use this information to design and test rehabilitation and prevention strategies for these conditions. Studies have been designed to test the general hypothesis that mechanical low back pain (MLBP) results, in part, from a tendency of the lumbar spine to favor movement in a specific direction when moving the trunk or limbs. The tendency to move in a specific direction is proposed to develop as a consequence of repetition of movements performed during daily work and leisure activities. The experiments will address whether or not (1) distinguishable groups of MLBP can be identified based on direction-specific impairments measured during a clinical examination, (2) there is a relationship between the specific directions in which trunk movements are performed repeatedly and specific types of movement impairments identified in people with MLBP, and (3) there are altered patterns of trunk muscle recruitment in people with MLBP that perform trunk movements repeatedly in a specific direction. To address these hypotheses, data from tests from a clinical examination that assesses direction-specific, mechanically-based impairments, as well as kinematic and electromyographic (EMG) data will be examined. In the first experiment, a data set of direction-specific clinical examination variables from people with MLBP will be tested for the presence of distinguishable groups of MLBP using advanced, multivariate techniques. A second experiment will compare the number and extent of direction-specific impairments in a cohort of people with MLBP performing repeated trunk movements in a specific direction, and a control group. A third experiment will examine the relationship between hip and trunk rotation impairments in people with and without MLBP performing repeated trunk rotation movements. Finally, trunk muscle recruitment patterns during extremity movements will be compared in a cohort of people with MLBP performing repeated trunk movements in a specific direction, and a control group. The proposed experiments are designed to determine the nature of the movement impairments in MLBP and to relate these impairments to specific, everyday activities the persons perform repeatedly.